1. Field of the Invention
The present invention relates to a living body impedance measurement apparatus in which actually measured living body impedance is separated into resistance component and reactance component in order to provide the true impedance of the living body.
2. Prior Art
An impedance measurement method has been developed (see Japanese Patent No. 2835656) wherein a set of several reference resistors each having the predetermined resistance to properly divide the measured living body impedance is provided in a current supplying path in series with a living body for measuring the impedance thereof, then, voltage drop across each of the reference resistors and voltage drop across the living body are measured; thereafter, based on the resistance values of the reference resistors and the corresponding voltage values measured thereacross a correlation formula for correlating therebetween is determined; and the living body impedance is calculated by the determined correlation formula, depending on the voltage measured across the living body.
Unfortunately, such previous impedance measurement method entails presence of some impedance change factors in a sinusoidal wave generator for producing constant current, a voltage/current converter, and a current supplying path, for example. Therefore, the previous measurement method is defective in that the living body impedance resulted from the measurement and calculation process is frequently lack of precision.
In view of the above it is an object of the present invention to solve the problem in the prior art as described above and to provide an improved living body impedance measurement apparatus having capability of measurement with higher precision and having less effect on the measurement by any fluctuation which may be caused due to presence of any impedance change factors.